Regulation of Flagellum Biosynthesis in Response to Cell Envelope Stress in Serovar Typhimurium.
Cast your vote
You can rate an item by clicking the amount of stars they wish to award to this item.
When enough users have cast their vote on this item, the average rating will also be shown.
Your vote was cast
Thank you for your feedback
Thank you for your feedback
MetadataShow full item record
AbstractFlagellum-driven motility of serovar Typhimurium facilitates host colonization. However, the large extracellular flagellum is also a prime target for the immune system. As consequence, expression of flagella is bistable within a population of , resulting in flagellated and nonflagellated subpopulations. This allows the bacteria to maximize fitness in hostile environments. The degenerate EAL domain protein RflP (formerly YdiV) is responsible for the bistable expression of flagella by directing the flagellar master regulatory complex FlhDC with respect to proteolytic degradation. Information concerning the environmental cues controlling expression of and thus about the bistable flagellar biosynthesis remains ambiguous. Here, we demonstrated that RflP responds to cell envelope stress and alterations of outer membrane integrity. Lipopolysaccharide (LPS) truncation mutants of Typhimurium exhibited increasing motility defects due to downregulation of flagellar gene expression. Transposon mutagenesis and genetic profiling revealed that σ (RpoE) and Rcs phosphorelay-dependent cell envelope stress response systems sense modifications of the lipopolysaccaride, low pH, and activity of the complement system. This subsequently results in activation of RflP expression and degradation of FlhDC via ClpXP. We speculate that the presence of diverse hostile environments inside the host might result in cell envelope damage and would thus trigger the repression of resource-costly and immunogenic flagellum biosynthesis via activation of the cell envelope stress response. Pathogenic bacteria such as Typhimurium sense and adapt to a multitude of changing and stressful environments during host infection. At the initial stage of gastrointestinal colonization, uses flagellum-mediated motility to reach preferred sites of infection. However, the flagellum also constitutes a prime target for the host's immune response. Accordingly, the pathogen needs to determine the spatiotemporal stage of infection and control flagellar biosynthesis in a robust manner. We found that uses signals from cell envelope stress-sensing systems to turn off production of flagella. We speculate that downregulation of flagellum synthesis after cell envelope damage in hostile environments aids survival of during late stages of infection and provides a means to escape recognition by the immune system.
The following license files are associated with this item:
Except where otherwise noted, this item's license is described as Attribution-NonCommercial-ShareAlike 3.0 United States
- A nutrient-tunable bistable switch controls motility in Salmonella enterica serovar Typhimurium.
- Authors: Koirala S, Mears P, Sim M, Golding I, Chemla YR, Aldridge PD, Rao CV
- Issue date: 2014 Aug 26
- Coupling of flagellar gene expression to flagellar assembly in Salmonella enterica serovar typhimurium and Escherichia coli.
- Authors: Chilcott GS, Hughes KT
- Issue date: 2000 Dec
- Curcumin Reduces the Motility of Salmonella enterica Serovar Typhimurium by Binding to the Flagella, Thereby Leading to Flagellar Fragility and Shedding.
- Authors: Marathe SA, Balakrishnan A, Negi VD, Sakorey D, Chandra N, Chakravortty D
- Issue date: 2016 Jul 1
- The ClpXP ATP-dependent protease regulates flagellum synthesis in Salmonella enterica serovar typhimurium.
- Authors: Tomoyasu T, Ohkishi T, Ukyo Y, Tokumitsu A, Takaya A, Suzuki M, Sekiya K, Matsui H, Kutsukake K, Yamamoto T
- Issue date: 2002 Feb
- EAL domain protein YdiV acts as an anti-FlhD4C2 factor responsible for nutritional control of the flagellar regulon in Salmonella enterica Serovar Typhimurium.
- Authors: Wada T, Morizane T, Abo T, Tominaga A, Inoue-Tanaka K, Kutsukake K
- Issue date: 2011 Apr